It's not that these techniques don't work at all. The problem is that they are so low percentage they are generally not worth wasting the amount of training time needed to become proficient in them. That time is much better of being spent on high percentage moves judo/wresting takedowns, strikes, chokes, ground fighting arm locks and leg locks. I did manage to pull off a few in South Korea in the 80s, the KNP thought it was really cool.

If you browse around there's a vid of him breaking an arm with the exact technique.

Aren't the standing "lock and throw" techniques banned from amateur MMA for being too injury-prone? Read that somewhere...

As far as using standing arm locks for submission, a retired LEF buddy of mine once told me it really requires a wall, the ground, or a squad car to work properly against a fully resisting suspect, but is effective when trying to gain compliance from most individuals (marginal to no effective resistance).

My experience with standing joint locks in my JJJ dojo is that they're certainly not impossible to pull off, but most people beneath blue/brown belt level basically can't pull them off on a resisting partner, and even then those people usually have to resort to some kind of atemi (as discussed above) or switching from technique to technique 3-4 times before getting something to stick. Curiously, people attempting the Nage Waza of the curriculum (which is 95% straight from Judo) enjoy much better results; they're simply not high-percentage techniques against trained opponents that know to look for it.

Its also just a lot harder to "set up" joint locks as opposed to striking combinations, because resistance to a lock is more unpredictable. If he's not immobilized, you can't just decide that you're going to use xyz lock -- its more of a spontaneous response to whatever is going on at the time.

Precisely. At least one of those is readily available. If and when necessary, just combine your standing joint lock with something appropriate like (in some cases) a nice o-soto, and you're good to go.